TEKS 8.6 C
I’m Depending on You
TAKS Objective 2 – The student will demonstrate an understanding of
living systems and the environment.
Learned Science Concepts:



Interdependence occurs among living systems.
Traits of species can change through generations.
The instructions for traits are contained in the genetic material
of the organisms.
TEKS Science Concepts 8.6
The student knows that interdependence occurs among living systems. The
student is expected to:
(C) describe interactions within ecosystems.
Overview
In the lesson the student uses plastic soda bottles to build an ecocolumn which
will be used to study biotic and abiotic interactions in terrestrial and acquatic
systems (e.g., food chains, food webs, competition, chemical and nutrient
cycling). The ecocolumn structure will be used to further understandings about
how salt, fertilizer, and acid rain upset the balance of ecosystems (TEKS 8.14 C).
TAKS Objective 2
page 1
TEKS 8.6 C
Instructional Strategies
Student will work individually or in pairs to construct ecocolumns individually or
in pairs. Guided inquiry will be used to deepen student understandings of
ecosystems. As students gain an understanding of the control column, they will
conduct investigations that explore how salt, fertilizer, and acid rain affect
ecosystems.
Lesson Objectives
1. After constructing and observing the balanced ecocolumn, the learner will
produce a graph or sketch to accurately describe at least one example of
oxygen and carbon dioxide cycling in the ecocolumn.
2. After constructing the terrarium and acquarium for the ecocolumn, the
learner will record observations and drawings for each plant and animal in
the ecocolumn.
3. Using an ecocolumn, the learner will demonstrate an understanding of
food chains by accurately drawing a food chain and a foodweb.
4. Using the data collected from the “Observing the Effects of Pollution on
Plant and Animal Life” worksheet, the learner will write at least 50 words
in their science journal describing the effects of pollution on terrestrial and
aquatic plant life.
TAKS Objective 2
page 2
TEKS 8.6 C
For Teacher’s Eyes Only
Teacher Background: The combination of abiotic factors and communities in
an environment is called an ecosystem. Abiotic factors include water, soil,
wind, temperature, and light. A community includes the different species which
interact in the ecosystem and depend on one another for survival. An ecosystem
may be small, such as pond, or large such as a forest. If any part of the ecosystem
suddenly changes, serious problems can result affecting the whole ecosystem.
TEKS 8.14 examines the impact of natural events and human activity on
ecosystems.
In an ecosystem energy flows from the sun to autotrophs and subsequently to
heterotrophs as energy is transferred in a food chain. At each level, some of the
energy is used by the organism and some of the energy is lost as heat. About 10%
of the energy is transferred between trophic levels. Additionally, the number of
organisms at a given trophic level depends on the biomass and energy present in
the trophic level below it. In general, decreases in the number or organisms
accompany increasingly higher trophic levels. Also, heterotrophs, depending on
variations in diet, are found at different trophic levels and in different food chains.
Finally, pollutants such as DDT increase in concentration as they move up the
food chain due to the biological magnification.
Nutrients must be recycled in the ecosystem. The processes of photosynthesis
and cellular respiration are used to recycle oxygen and carbon. It is also possible
for carbon to be stored in organisms and fossil fuels. Nitrogen is released by
decomposers and fixing bacteria utilized by plants provides a source of nitrogen
that may be used by other organisms to form proteins and nucleic acids. Nitrogen
may be returned to the soil via fertilizer.
Water cycles through living organisms. For example, plants take up water
through their roots and water exits plant leaves during transpiration. Similarly,
animals take in water when they eat or drink. This water is subsequently returned
to the environment via urination, water vapor from respiration, and sweat. The
water cycles in the environment is powered by the sun, and moves water
between the earth’s surface and the atmosphere through the processes of
precipitation, evaporation, and transpiration.
TAKS Objective 2
page 3
TEKS 8.6 C
Misconceptions
 Misconception
Plants do not carry on respiratory functions.
 Science Concept
Plants require energy for cell functions. Plants use stomata to take in
oxygen instead of lungs or gills.
Rebuild Concept
Provide experiences that demonstrate how plants are affected with O2
levels are low.
 Misconception
The majority of O2 is provided by terrestrial plants.
 Science Concept
The majority of O2 is produced by phytoplankton and algae living in the
oceans.
Rebuild Concept
Compare the biomass of phytoplankton, algae, and terrestrial plants. Since
the world is about 70% ocean and phytoplankton are distributed
throughout the ocean, they provide about 90% of the O2 some of which
stays in the ocean, but most of which escapes as a gas into the atmosphere.
TAKS Objective 2
page 4
TEKS 8.6 C
Student Prior Knowledge
The teachers should make sure students are familiar with the components of an
ecosystem (TEKS 7.12 A) and the flow of energy in living systems including food
chains and food webs (TEKS 6.8 C). The role of ecological succession with
regard to environmental change and equilibrium (7.12 D and 7.5 B) as well as the
relationship between producers, consumers, and decomposers in an ecosystem
should be reviewed. Finally, students should have an understanding about the
relationship between organisms and the environment they are found in (7.12 C).
TAKS Objective 2
page 5
TEKS 8.6 C
Ecosystems
5 E’s
ENGAGE
Show pictures of the Exxon Valdez oil spill.
http://www.evostc.state.ak.us/facts/photos.html
EXPLORE
Create an ecocolumn to help students review prior knowledge about ecosystems.
The ecocolumn will be used in tandem with TEKAS 14 C which investigates the
effects of pollution on an ecosystem (TEKS 14 C).
Materials:
3 – 2-liter plastic soda bottles (labels removed)
3 – 10 oz plastic cups
Metric ruler
Plastic spoon
Hand lens
Dip net
TAKS Objective 2
page 6
TEKS 8.6 C
Terrarium
Aquarium
1 – 8 cm. square of fiberglass screen
Water conditioner
2 cups soil
1 cup gravel
1 cup water
1 liter prepared water
1 cup gravel
3-4 sprigs Elodea
Various seeds (rye, alfalfa, mustard)
20 mL algae
1 rubber band
2 pond snails
2 pill bugs
1 small aquatic frog or two mosquito
fish
2 crickets
Procedure to create an ecocolumn:
Bottle #1
1. Create a terrarium by measuring 23 cm. from the top pouring spout of the
first 2-liter plastic soda bottle and marking a circle around the
circumference of the bottle. Use scissors to cut off the bottom of the
bottle. Save the bottom of the bottle to cap the terrarium to prevent the
crickets from escaping. Use a hole punch or awl to create 6-8 holes to
allow air to enter the bottle.
Bottle #2
2. Create a connector for the terrarium and aquarium by measuring 9 cm
from the top pouring spout of the second 2-liter plastic soda bottle and
marking a circle around the circumference of the bottle. Measure 23 cm.
from the top of the same 2-liter plastic soda bottle and mark a second
circle around the circumference of the bottle. Use scissors to cut off the
top and the bottom of the bottle. Save the middle of the bottle (connector).
Discard the top and bottom of the bottle in a recycling bin.
Bottle #3
3. Create an aquarium by measuring 11 cm. from the top of the third 2-liter
plastic soda bottle and marking a circle around the circumference of the
TAKS Objective 2
page 7
TEKS 8.6 C
bottle. Use scissors to cut off the bottom of the bottle. Discard the bottom
of the bottle in a recycling bin.
Terrarium Setup:
1. Wrap the square of fiberglass screen over the pouring spout of the bottle.
Use a rubber band to secure the fiberglass screen.
2. Stand the bottle pouring spout down in a plastic cup.
3. Add 1 cup of gravel to the bottle.
4. Add 2 cups of soil on top of the gravel.
5. Add at least 10 seeds to the bottle. If more than one type of seeds is added
be sure to use a permanent marker to indicate their location on the outside
of the bottle.
6. Add water until the water begins to drip from the fiberglass screen over
the pouring spout of the bottle. Replace the bottle cap.
7. After 14 days, add two crickets and two pill bugs. In order to prevent the
crickets from jumping out of the terrarium, cover the terrarium with a
suitable material (e.g., net) until the ecocolumn is fitted together.
Aquarium setup:
1. Add 1 cup gravel to the bottom of the aquarium
2. Fill the aquarium with conditioned* water. Leave approximately 4 cm of
space between the waterline and the top of the aquarium.
3. Add 20 mL of algae and 2 sprigs of Elodea to the aquarium.
4. Use a dip net to transfer an aquatic frog OR mosquito fish to the aquarium.
5. Use a plastic spoon to transfer two pond snails to the aquarium.
Fitting the pieces together:
Use the connector to join the terrarium to the aquarium. The aquarium goes on the
bottom of the ecocolumn and the terrarium goes on the top of the ecocolumn.
TAKS Objective 2
page 8
TEKS 8.6 C
EXPLAIN
Ask students to explain the relationship between O2 and CO2 in the ecocolumn.
Students should be able to articulate the role of solar energy, respiration and
photosynthesis. The students should understand that the process of photosynthesis
combines solar energy, water and carbon dioxide which is used to sustain
autotrophic organisms. Simultaneously, the process of respiration is used by
organisms which take in oxygen used for energy and expel carbon dioxide as a
waste product. Finally, there is a continuous cycling of oxygen and carbon
dioxide in our environment. The teacher may want the students to make a diagram
of this relationship.
There are also a number of observations students can make about the plants in the
aquarium and the terrarium (e.g., shape, size, color, root system, adaptations, and
life cycle). Similarly, a number of observations can be made about the animals in
the aquarium and terrarium (e.g., locomotion, competition, respiration, feeding,
molting). Students should also create food chains and webs based on their
observations and answer questions about how the two ecosystems are related.
ELABORATE
Use the ecocolumn design to conduct pollution experiments (TEKS 8.14 C in
chapter 5). Work with a partner to determine which type of pollution to
investigate (i.e., acid rain, chemical fertilizers, salt). Decide on the concentration
of the pollution solution and how often the pollution solution will be administered
(e.g., daily and/or weekly).
Pollution Solutions:
1. Normal rain has a pH of 5.6. Acid rain has a pH of less than 5.6. A
solution of imitation acid rain can be made by combining 10 mL or more
of vinegar with 1 liter of water. Create a solution of acid rain. Record the
ratio of vinegar to water in your science journal. Use the handout to record
observations about the effect of pollution on plant and animal life.
TAKS Objective 2
page 9
TEKS 8.6 C
2. Chemical fertilizers used in agriculture artificially increase available
nutrients to organisms. The recommended amount of fertilizer used in
agriculture is 1.25 mL per liter of water. However, agricultural runoff can
add 10 times the recommended amount of fertilizer to our water. Create a
solution of fertilizer. Record the ration of fertilizer to water in your
science journal. Use the handout to record observations about the effect of
pollution on plant and animal life.
3. Every year, the highway department spread a mixture of salt and sand to
help melt ice on roads. The edge of the road is polluted with
approximately 6 ml per liter of water. Eventually, salt filters through the
soil and contaminates water systems. Create a solution of salt water.
Record the ratio of salt to water in your science journal. Use the handout
to record observations about the effect of pollution on plant and animal
life.
EVALUATE
5. After constructing and observing the balanced ecocolumn, the learner will
produce a graph or sketch to accurately describe at least one example of
oxygen and carbon dioxide cycling in the ecocolumn.
6. After constructing the terrarium and acquarium for the ecocolumn, the
learner will record observations and drawings for each plant and animal in
the ecocolumn.
7. Using an ecocolumn, the learner will demonstrate an understanding of
food chains by accurately drawing a food chain and a foodweb.
8. Using the data collected from the “Observing the Effects of Pollution on
Plant and Animal Life” worksheet, the learner will write at least 50 words
in their science journal describing the effects of pollution on terrestrial and
aquatic plant life.
TAKS Objective 2
page 10
TEKS 8.6 C
TAKS Objective 2
page 11
TEKS 8.6 C
Ecocolumns
Create an ecocolumn using the following materials and direction:
Materials:
3 – 2-liter plastic soda bottles (labels removed)
1 – 2-liter plastic soda bottle cap
3 – 10 oz plastic cups
Metric ruler
Plastic spoon
Hand lens
Dip net
Terrarium
Aquarium
1 – 8 cm. square of fiberglass screen
Water conditioner
2 cups soil
1 cup gravel
1 cup water
1 liter prepared water
1 cup gravel
2 sprigs Elodea
Various seeds (rye, alfalfa, mustard)
20 mL algae
1 rubber band
2 pond snails
2 pill bugs
1 small aquatic frog or two mosquito
fish
2 crickets
TAKS Objective 2
page 12
TEKS 8.6 C
Procedure to create an ecocolumn:
Bottle #1

Create a terrarium by measuring 23 cm. from the top pouring spout of the
first 2-liter plastic soda bottle and marking a circle around the
circumference of the bottle. Use scissors to cut off the bottom of the
bottle. Save the bottom of the bottle.
Bottle #2

Create a connector for the terrarium and aquarium by measuring 9 cm
from the top pouring spout of the second 2-liter plastic soda bottle and
marking a circle around the circumference of the bottle. Measure 23 cm.
from the top of the same 2-liter plastic soda bottle and mark a second
circle around the circumference of the bottle. Use scissors to cut off the
top and the bottom of the bottle. Save the middle of the bottle (connector).
Discard the top and bottom of the bottle in a recycling bin.
Bottle #3

Create an aquarium by measuring 11 cm. from the top of the third 2-liter
plastic soda bottle and marking a circle around the circumference of the
bottle. Use scissors to cut off the bottom of the bottle. Discard the bottom
of the bottle in a recycling bin.
Terrarium Setup:
1. Wrap the square of fiberglass screen over the pouring spout of the bottle.
Use a rubber band to secure the fiberglass screen.
2. Stand the bottle pouring spout down in a plastic cup.
3. Add 1 cup of gravel to the bottle.
4. Add 2 cups of soil on top of the gravel.
5. Add at least 10 seeds to the bottle. If more than one type of seeds is added
be sure to use a permanent marker to indicate their location on the outside
of the bottle.
6. Add water until the water begins to drip from the fiberglass screen over
the pouring spout of the bottle. Replace the bottle cap.
7. After 14 days, add two crickets and two pill bugs. In order to prevent the
crickets from jumping out of the terrarium, cover the terrarium with a
suitable material (e.g., net) until the ecocolumn is fitted together.
TAKS Objective 2
page 13
TEKS 8.6 C
Aquarium setup:
1. Add 1 cup gravel to the bottom of the aquarium
2. Fill the aquarium with conditioned* water. Leave approximately 4 cm of
space between the waterline and the top of the aquarium.
3. Add 20 mL of algae and 2 sprigs of Elodea to the aquarium.
4. Use a dip net to transfer an aquatic frog OR mosquito fish to the aquarium.
5. Use a plastic spoon to transfer two pond snails to the aquarium.
Fitting the pieces together:
Use the connector to join the terrarium to the aquarium. The aquarium goes on the
bottom of the ecocolumn and the terrarium goes on the top of the ecocolumn.
TAKS Objective 2
page 14
TEKS 8.6 C
Ecocolumn Pollution Experiment
Use the ecocolumn design to conduct pollution experiments. Work with a partner
to determine which type of pollution to investigate (i.e., acid rain, chemical
fertilizers, salt). Decide on the concentration of the pollution solution and how
often the pollution solution will be administered (e.g., daily and/or weekly).
Pollution Solutions:
1. Normal rain has a pH of 5.6. Acid rain has a pH of less than 5.6. A
solution of imitation acid rain can be made by combining 10 mL or more
of vinegar with 1 liter of water. Create a solution of acid rain. Record the
ratio of vinegar to water in your science journal. Use the handout to record
observations about the effect of pollution on plant and animal life.
2. Chemical fertilizers used in agriculture artificially increase available
nutrients to organisms. The recommended amount of fertilizer used in
agriculture is 1.25 mL per liter of water. However, agricultural runoff can
add 10 times the recommended amount of fertilizer to our water. Create a
solution of fertilizer. Record the ration of fertilizer to water in your
science journal. Use the handout to record observations about the effect of
pollution on plant and animal life.
3. Every year, the highway department spread a mixture of salt and sand to
help melt ice on roads. The edge of the road is polluted with
approximately 6 ml per liter of water. Eventually, salt filters through the
soil and contaminates water systems. Create a solution of salt water.
Record the ratio of salt to water in your science journal. Use the handout
to record observations about the effect of pollution on plant and animal
life.
TAKS Objective 2
page 15
TEKS 8.6 C
Observing the Effects of Pollution on Plant and Animal Life
Experimental Ecocolumn
Date
Terrarium pH
Aquarium pH
Plant
Observations
Control Ecocolumn
Animal
Observations
TAKS Objective 2
Terrarium pH
page 16
Aquarium pH
TEKS 8.6 C
Plant
Observations
Animal
Observations